Allicin inhibits spontaneous and TNF-α induced secretion of proinflammatory cytokines and chemokines from intestinal epithelial cells

Background & aims: Allicin, the active substance of fresh crushed garlic has different biological activities and was implicated as an anti-inflammatory agent. Epithelial cells have an important role in intestinal inflammation. The aim of this study was to assess the immunomodulatory effect of allicin on intestinal epithelial cells. Methods: The spontaneous and TNF-α-stimulated secretion of IL-1β, IL-8, IP-10 and MIG from HT-29 and Caco-2 cells was tested with, or without pretreatment with allicin. Cytokine secretion was assessed using ELISA and expression of mRNA was determined by an RNA protection assay. Results: Allicin markedly inhibited the spontaneous and TNF-α -induced secretion of IL-1β, IL-8, IP-10 and MIG from the two different cell lines in a dose-dependent manner and suppressed the expression of IL-8 and IL-1β mRNA levels. In addition, allicin suppressed the degradation of IκB. No effect on cell viability was noted. Conclusions: These observations indicate that allicin exerts an inhibitory immunomodulatory effect on intestinal epithelial cells and suggest that allicin may have the potential to attenuate intestinal inflammation.